There are mainly three possible case:1) The content of your .ISO image is an AVI-DV file, but with wrong extension .ISO2) Your .ISO image is corrupted. We have received many BLANK sample images. (downloaded from third-party sites)3) Your .ISO image have UDF volume ONLY, currently UltraISO cannot handle this kind of ISO

Test and confirm: You can emulate your ISO image by CD emualoters, such as SoftDisc and Alcohol, then try to access the virtual CD/DVD-ROM by windows explorer